Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cau tren » cu tren, dau tren, cau treo
sach ky » sac ky, sach ty, sach kem
va hanh » van hanh, va thanh, va danh
ca tren » cu tren, la tren, co tren
nam tu » nam thu, nam thuc
x hoi » xa hoi, o hoi, x ho

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) OR (sach y)) nang x hoi. hieu van nam tu va hanh vi ((ca tren) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach y)) nang x hoi. hieu van nam tu va hanh vi ((ca tren) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) OR (sach y)) nang x hoi. hieu van nam tu va hanh vi ((ca tren) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) OR (sach y)) nang x hoi. hieu van nam tu va hanh vi ((ca tren) or (cau tren))*.